超宽大跨系杆拱桥横梁安装顺序对纵梁的受力影响研究

Analysis on Effect of Crossbeam Erection Sequence on Longitudinal Beam Stress of Super-wide Long-span Bowstring Arch Bridge

超宽系杆拱桥由于横梁和纵梁分别预制吊装,横梁合拢钢束的张拉会使纵梁产生面外弯矩从而影响纵梁应力,导致纵梁同一截面高度处中间位置应力和边缘位置应力存在差异。该差异很可能使纵梁计算成为桥梁结构计算的关键控制节点。为寻求较优的解决方案,避免盲目增大截面或钢束从而造成资源浪费,以湖州市经济开发区环漾大桥新建工程为背景,从横梁施工工序的角度出发,试算了几种施工工序,找出对纵梁受力最有利的施工工序作为本工程最终的横梁安装顺序,最大化缩小上述应力差异,达到结构设计经济性和受力合理性的目标。

The tension of the closure steel cable of crossbeam will make the longitudinal beam produce an out-of-plane bending moment because of the crossbeam and longitudinal beam of the ultra-wide bowstring arch bridge respectively prefabricated and hoisted, which will affect the stress of longitudinal beam and cause the difference between the intermediate position stress and the edge position stress at the same section height of the longitudinal beam. This difference is likely to make the calculation of longitudinal beam become a key control node for the calculation of bridge structure. In order to seek a better solution and avoid blindly increasing the section or steel bundle, which will cause a waste of resources, this paper tests several construction procedures from the viewpoint of crossbeam construction procedure according to the background of the new construction project of Huanyang Bridge in Huzhou Economic Development Zone, and tries to find out the most favorable construction procedure of the longitudinal beam stress as the final crossbeam erection sequence of the project, to maximize the reduction of the above stress differences and to achieve the goal of structural design economy and stress rationality.